Semi-automatic insert tool

ABSTRACT

The disclosure relates to a semi-automatic helical insert tool that supports a pair of coils of feed strip having helical inserts thereon. The feed strip is fed through a strip guide to an indexing dial which advances an insert into drive position upon reciprocation of a manually operable trigger on the tool. Actuation of the trigger of the tool not only advances the helical insert into drive position but actuates an air motor to effect advancement of a drive tool into engagement with the insert and drive of the insert into a complementary aperture in a workpiece.

BACKGROUND OF THE INVENTION

Thread inserts are often utilized in relatively soft materials that arerequired to repeatedly accept complementary fasteners. Such inserts aregenerally made from relatively hard material and have an external threadthat is engageable in the soft material and an internal thread ofrelatively smaller pitch diameter that accommodates the complementarythreaded fastener. The resultant fastening installation exhibits asignificant increase in structural strengh and integrity overinstallations wherein the fastener is threaded directly into the softermaterial.

Since locking inserts are an additional structural element in anyassembly over and above the threaded aperture in the parent material,installation thereof entails an increase in labor as well as thematerial cost of the insert. Accordingly, every effort is made toassemble the inserts into complementary holes in a parent material atmaximum speed consistent with structural integrity of the completedassembly.

It has heretofore been proposed to drive helical inserts intocomplementary threaded holes in a parent material by either a hand toolhaving a nose portion engageable with a tang on the insert or by airpowered tools having a driving nose that is engageable with a tang onthe insert in the manner similar to the manual tool. Tools for insertinginserts into a relatively soft workpiece are taught in U.S. Pat. Nos.2,371,622; 2,855,661; 3,093,895; 3,111,751 and 3,579,793. While thepower tool of U.S. Pat. No. 3,579,793 materially speeds up theinstallation process, the limiting factor in speed of application is thefeed of the inserts to the tool. While inserts have been mounted onstrips for feed to a tool as taught in Swedish Letters Patent No.341,994, a need has developed in the marketplace for a tool that ispositive in operation and that maximizes magazine capacity. The toolshould preferably be semi-automatic in nature requiring a singleactuation to effect both advancement of an insert into drive position,actuation of the driving tool, and drive of the insert into acomplementary hole in a workpiece.

SUMMARY OF THE INVENTION

A semi-automatic helical insert tool in accordance with the instantinvention features a frame of pistol grip configuration for theacceptance of a conventional air motor. The air motor and insert drivinghead thereon is similar to the tool disclosed and claimed in U.S. Pat.No. 3,579,793. Accordingly, no detailed description thereof is madeherein for the purpose of simplicity.

The tool of the instant invention features a pair of coaxially relatedrotary magazines that advance a feed strip having inserts thereon to aninstallation position. Two spools of feed strip are stored in themagazine and are selectively fed to the drive mechanism of the tool.

Advancement of the feed strip and inserts thereon to a drive position isaccomplished by a novel strip feed indexing dial which has lugs thereonthat engage in complementary notches in the feed strip to effectadvancement thereof upon rotation of the dial. Rotation of the dial iseffected by an index gear which is actuated by a ratchet arm and triggerassembly. A single pull on the trigger effects mechanical advancement ofthe feed strip and helical insert to a drive position and subsequentlyeffects energization of the air motor of the tool. Advancement of aconventional drive head effects engagement of the insert and drivethereof into the workpiece. The tool is provided with a novel feed stripcutoff mechanism to dispose of empty feed strip after it passes throughthe drive station of the tool.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevational view, partially in section, of a semi-automaticinsert tool of the instant invention.

FIG. 2 is a view, partially in section, taken in the direction 2 of FIG.1.

FIG. 3 is an enlarged view taken in the direction of the arrow 3 of FIG.1.

FIG. 4 is an enlarged view taken within the circle 4 of FIG. 1.

FIG. 5 is a view of the strip spool that is acceptable in the magazineshown in FIG. 1 of the drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

As best seen in FIG. 1 of the drawings, a semi-automatic helical inserttool 10 comprises a frame 12 having a pistol grip 14 thereon tofacilitate hand operation of the tool 10. The frame 12 has a cylindricalrecess 16 therein for the acceptance of a conventional air motor 18. Theair motor 18 is similar to the motor disclosed in U.S. Pat. No.3,579,793 and reference should be made thereto for details. The airmotor 18 has a conventional air inlet nozzle 20 for connection to asource of high pressure air, not shown.

The air motor 18 is actuated by an air control valve actuator 22 whichin turn is actuated by a trigger pivot 24. The trigger pivot 24 isbiased to the on position, as seen in FIG. 1 of the drawings, by a camsurface 26 of a trigger 28. The trigger is orientated relative to thehandle 14 to facilitate operation thereof by the finger of an operator.

The trigger 28 is connected through a ratchet pull rod 30 to a ratchetbracket 32. The ratchet pull rod 30 is normally biased to the left, asseen in FIG. 1 of the drawings, by helical compression spring 34 whichexerts a bias in the opposite direction to that of the finger of anoperator within the trigger 28.

Movement of a ratchet arm 36 on the bracket 32 to the right under thebias of the trigger 28 effects movement of a pin 40 thereon to theright. The pin 40 is engaged in complementary teeth 42 in an index gear44. The index gear 44 is journaled on a shaft 46, as is a feed dial 48.The index gear 44 and feed dial 48 are pinned to one another forconcomitant rotation so as to effect feed of a feed strip 50, as will bedescribed.

The feed dial 48 is provided with a plurality of radially outwardlyextending dogs 52 which are acceptable in complementary notches 54 inthe feed strip 50. Each reciprocation of the pin 40 on the ratchet arm36 to the right, as seen in FIG. 1 of the drawings, effects advancementof one helical insert 56 into a feed position coaxial with the axis ofrotation of the air motor 18. An insert drive assembly 60 is provided onthe front end of the air motor 18 which is similar to that disclosed inU.S. Pat. No. 3,579,793, which forms no part of the instant invention.

As best seen in FIG. 4 of the drawings, the drive assembly 60 of the airmotor 18 is provided with a cutoff mechanism for empty feed strip. Moreparticularly, a cutoff blade 62 is journaled on a cylindrical endportion 64 of the drive assembly 60. A cutting edge 66 on the cutoffblade 62 is advanced relative to the feed strip 54 by a hand lever 68.Rotation of the lever 68 effects rotation of an eccentric 69 relative tothe drive assembly end portion 64 and advancement of the cutting edge 66into engagement with the feed tape 54 thereby to cut the empty tape 54.

As seen in FIG. 5 of the drawings, a spool 70 accommodates two coils offeed strip 54. As seen in FIG. 2, the feed strips 54 on the spool 70 arefed to the drive assembly of the tool 10 one at a time, the strips 54being manually inserted into a complementary slot 72 in a strip guide 74to effect loading.

While the preferred embodiment of the invention has been disclosed, itshould be appreciated that the invention is susceptible of modificationwithout departing from the scope of the following claims.

I claim:
 1. A semi-automatic helical insert tool comprisinga frame, amotor on said frame having an insert driving head thereon, a feed striphaving a plurality of drive notches therein, a plurality of inserts insaid feed strip, a circular magazine on said frame having a rotatablespool therein for supporting said feed strip, a feed dial having teethengageable in the notches in said feed strip, a manually operabletrigger, mechanical means comprising an index gear having ratchet teeththereon rotatable with said feed dial, and a pawl actuatable by saidtrigger and engageable with said ratchet teeth, said means beingactuatable upon a predetermined first increment of travel of saidtrigger in one direction for advancing said feed dial and one insert onsaid feed strip to a drive position in alignment with the tool on saidmotor each time said trigger is pulled, and control means for said motorenergizable upon a predetermined travel of said trigger in said onedirection to energize said motor to advance said tool into engagementwith an insert and advance said insert into a workpiece.